Slot machines having progressive jackpots are well known. Examples of such machines are found in U.S. Pat. Nos. 5,048,833, 5,249,800, and 5,280,909, incorporated herein by reference. In existing devices, a small percentage of each amount bet in either one machine or a group of machines is allocated to a progressive jackpot. A special symbol combination is designated as the progressive jackpot winner. When this jackpot symbol combination is obtained by a slot machine, the progressive jackpot is awarded to that player, and the jackpot is reset to an initial amount. The initial amount may be zero or any other predetermined amount. In such machines, there is typically only one progressive jackpot.
Slot machines which generate higher revenues for the machine owner are more valuable to the machine owner. Thus, any feature that makes a slot machine more enticing to a player and causes the player to deposit more money into the machine is desirable.